Programmable logic controllers (PLCs) have been used extensively and are offered in terms of functions, program memories, and the number of inputs/outputs (I/Os), ranging from a few to thousands. With a focus on how to design and implement a PLC, this volume explains hardware and associated basic concepts of PLC. Authors have used PIC16F1847 microcontroller with: 8192 words of Flash program memory, 1024 bytes of SRAM data memory, 256 bytes of EEPROM data memory, the maximum operating speed of 32 MHz, 16-level deep hardware stack, an enhanced instruction set consisting of 49 single-word instructions. Flowcharts are provided to help the understanding of macros (instructions). Aimed at researchers and graduate students in electrical engineering, power electronics, robotics and automation, sensors, this book:Explains how to design and use a PIC16F1847 microcontroller-based PLC.Provides easy to use software structures written by using the PIC Assembly programming language.Describes a PLC from a designer's perspective.Explains the basic hardware and basic software structures of the PIC16F1847 based PLC.Focuses on concepts like Contact and Relay Based Macros, Flip-Flop Macros, Timer Macros, Counter Macros and Comparison Macros.